1. Field of the Invention
The present invention relates to flexible diaphragms used in flush valves, and more particularly, to flexible diaphragms with a segmented insert used in flush valves.
2. Description of Present Technology
Flush valves in water closets, urinals, and other plumbing devices, which utilize a flexible diaphragm to establish, and to seal off, the connection between the inlet and outlet sides of the flush valve are well-known in the art. Typically, the diaphragm is made of an elastomeric material, such as rubber, and includes a bypass orifice, which provides fluid communication between the inlet side of the flush valve and an upper chamber of the flush valve. An example of a typical diaphragm is shown in FIG. 1 of U.S. Pat. No. 5,232,194 to Saadi et al. (hereinafter also referred to as the “Saadi patent”); the disclosure of the Saadi patent is incorporated herein by reference.
The time cycle during which fluid, e.g. water, flows through the flush valve varies depending on the time it takes for a pressure drop to occur between the opposite sides of the diaphragm due to water passing through a bypass orifice into the upper chamber of the flush valve. Specifically, a pressure difference across the diaphragm causes water to pass through the flush valve for a fixed period of time when the flush valve is activated. As can now be appreciated, the bypass orifice of the diaphragm-type flush valves acts as a timing device. A detailed discussion of the operation of a diaphragm used with a flush valve can be found in column 1, lines 11-58 of the Saadi patent.
Recently, there has been some interest in filtering the water passing around the diaphragm to prevent clogging of the bypass orifice, which could undesirably effect the time period during which the flush valve is activated and/or the time of the flush valve refill cycle. U.S. Pat. No. 6,923,425 B2 to Verdecchia (hereinafter also referred to as the “Verdecchia patent”), which patent is hereby incorporated by reference, discloses a filtration system for preventing the clogging of the bypass orifice. In general, the Verdecchia patent discloses a flush valve diaphragm that includes a body portion and a peripheral sealing portion with the peripheral sealing portion including an integral filter. The integral filter prevents clogging of the bypass orifice. Although the presently available diaphragms are acceptable to prevent clogging of the bypass orifice, there are limitations. More particularly, the presently available diaphragms include a plurality of bendable or flexible metal inserts embedded in a rubber body to maintain the contour of the diaphragm as the upper surface of the diaphragm transitions from a concave shape to a convex shape, and the bottom surface, transitions from a convex shape to a concave shape, as the flush valve goes from the closed position to the open position.
Although metal plates are acceptable for use as inserts in flexible diaphragms of flush valves, it is appreciated by those skilled in the art, that it would be advantageous to have flexible diaphragms having a bendable insert of a different material that is lighter in weight than a plurality of metal inserts, and flexible diaphragms that are less expensive than diaphragms having a plurality of metal inserts.